Well, that's the part that I am finding difficult. I have some interesting topics to address; I have a decent amount of skill and experience at presenting; I have a lot of practice with internal audiences. But I am terrible at networking and this part you describe as "easy" is the stumbling block for me.
Do you have any specific pointers for finding events (even minor ones) which are local (I'm in the Philadelphia area, which is within driving distance of lots of east-coast places) and topical, and finding them EARLY enough to submit a speaking proposal?